It’s not uncommon for mechanics to be asked, “Why does my truck shake when I brake?” The car or truck is totally doing fine while driving at normal speeds, but as soon as you hit the brakes, the steering wheel shakes.
When your truck or car is functioning properly it should be running smoothly at all times and that includes when braking. So when your truck shakes when you’re hitting the brakes it can be a sign that your vehicle will need to be checked.
Why Does My Truck Shake When I Brake: How Brakes Work
To understand things better let us go back to how brakes work. It is the role of brakes to slow down a vehicle by impeding the ability of the wheels to turn. They slow the rotation of the wheels to slow the car.
Vehicles have 2 types of brakes and they are fitted on all current vehicles. The predominant type of brake is disc brakes, but a few cars still use drum brakes, commonly on the rear wheels. A metal disc, which is called the rotor, is coupled to the wheel in a disc brake and each rotor is fitted with a caliper, which is a clamping device that makes the rotor-and-wheel combination rotate freely unless the driver pushes the brake pedal.
The pressure as the driver pushes the brake pedal activates hydraulic fluid in the braking system bringing the brake pad within the caliper into contact with the disc, so it slows the wheel. More pressure on the brake pedal also creates more pressure in the hydraulic system, so the brake pad also clamps onto the rotor more tightly.
With drum brakes, on the other hand, a hollow metal drum is attached to the wheel. Once the hydraulic pressure is applied via the brake pedal and braking system it forces within the drum to apply friction to its inside circumference, and that slows the wheel. Once again, when pressure is applied to the brake pedal it results in more pressure applied by the brake shoes to the drum, and it slows the wheel more quickly.
Why Does My Truck Shake When I Brake: Common Reasons
You may want to troubleshoot your truck or take it straight to a mechanic but it always helps to know what could be going wrong so that you at least have an idea of what you should do. So when you ask, “why does my truck shake I brake,” these could be the reasons:
- Loose Tie Rod Ends and Steering Linkage
When you feel the shake as front brake pulsations are felt in the steering wheel the first thing that needs to be considered is the condition of the front steering linkage. Loose tie rod ends and steering linkage trends to magnify the issue or make the problem feel worse. Although for the most part these will not be the primary reason for the pulsations you will still need to be sure to address these problems first in addition to what is really causing the vibrations.
- Warped Rotors
One of the biggest reasons for shaking problems upon braking is your rotor’s condition. The rotor is the disc your brake pad clamps down on when you apply your brakes. When the rotors have some kind of imperfection on their surface or they have warped or changed shape over time, then vibration happens.
There are a few reasons why warping happens. It can be just a consequence of normal wear as the repeated pressure of the brake pad onto the rotor can wear away the rotor material in that specific contact area. Over time friction heat caused by the pad on the rotor can cause the rotor to warp.
The thickness of the rotors also plays a major role. As the rotors get thinned out over a lifetime of use, material from the rotors gets removed even with normal braking. As the rotors slowly get thinner, they are also able to less absorb the heat. With that possibility of damage also goes up.
Driving in steep areas where brakes have to be applied continuously on the downward slope will overheat the front brake rotors, and that also causes the rotors to warp. Another reason is a front caliper not retracting after braking causing overheating of the front brake rotors. This commonly is the case with cars or trucks with higher mileage vehicles when rust and corrosion prevents the calipers from retracting, and keeping the brake pads in contact with the brake rotors. So when you ask why does my truck shake when I brake, it’s probably the warped rotors.
Also when you have a brake job performed and the rotors have too much material removed, it can contribute to poor heat transfer, leading to rotors warping. The brake rotors and drums have minimum thickness that they can be turned down to. It’s also a must to machine-turn new rotors before they get installed as most rotors are not perfect when they are new. This is especially true when you buy rotors that have been stacked on top of each other in storage. This unfortunately warps rotors. So rotors have to be stored standing them on end preventing it from warping.
Over tightened front wheel lugs can also cause warped rotors. Wheel lugs have to be tightened with a torque wrench, allowing you to put the same tension on all the lug nuts. But over-tightening of these lug nuts can cause the rotors to warp. So never use an air-operated (pneumatic) impact wrench to tighten wheel lugs as it's very easy to over tighten the lugs when using this tool. A torque wrench is the only reliable tool to use to make sure if you've hit just the right tightness.
- Worn Brake Pads
Pressing down on the brake pedal kick starts a series of rapid events. As you step on the pedal the caliper will then apply pressure to the brake pad, which clinches down on the rotors bringing your vehicle to a stop. So if your brake pad has worn out, you may also feel it in your steering wheel. Old, dirty and worn out brake pads cannot grip the rotor effectively causing the steering wheel to quiver when you brake.
While calipers are built to last for a long time, the rotors and brake pads tend to wear out over time. But rotors can be resurfaced or replaced, and brake pads can easily be replaced as well.
- Dry Guide Pins
Dry guide pins could also be the reason when you have to ask yourself, “Why does my truck shake when I brake?” The guide pins are a component of the brake calipers, responsible for guiding (as the name suggests) the brake pad to the rotor. To function effectively, the guide pins have to be clean and lubricated. So if the guide pins dry out or corrode, they could cause the brake pads to press the rotor at a wrong angle or for the caliper to stick resulting in vibrations in the steering wheel.
Inspecting and lubricating the caliper guide pins involve taking it off and examining their housing, and handling high-temperature grease so this work is no simple DIY and best left to the professionals.
- Loose wheel bearings
Another possible answer to the question why does my truck shake when I brake is that you have loose wheel bearings. Behind each of a truck or car’s wheels is a wheel bearing that allows a wheel hub (a mounting point for the wheel and tire) to turn as the vehicle is traveling down the highway. And because the wheel hub also functions as a mounting spot for the disc brake, loose wheel bearings can lead to excessive lateral runout so you could experience shaking while braking.
- Worn suspension components
In some instances worn suspension components can also cause shaking while braking. The shaking sensation may be felt in the brake pedal and/or steering wheel. So picture this: in a strut-style suspension, the brake rotor is mounted to the steering knuckle, which is also mounted to the strut. With this, issues with the strut assembly can truck to shake when you brake.
- Tires Out of Alignment or Unbalanced Bad Tires
One possible cause of truck shaking when you hit the brakes, especially at high speeds on the road or when going downhill, is your tires. Check it first if you experience shaking when applying brakes. Your wheels might be out of alignment, or you have bad unbalanced tires.
You can check it out yourself if you have enough experience or know how or go to your car service provider to have the issue fixed easily. You might need to buy a new tire or two (best check the warranty of your tires if a replacement will be needed).
The car service provider might suggest front-end realignment, but take note that this will not be a permanent fix. Should you want to do your own alignment work take note that it will require expensive diagnostic equipment. Best ask for assistance as most garages charge less than $100 for the service, anyway.
Why does my truck shake when I brake? Other Frequently Asked Questions
- How do I know if my rotors are warped?
Warped rotors in the center will pulse the brake pedal, while front rotors will cause vibration through the steering wheel. If it is the rear rotors that have warped, then you will feel the vibration in the seat of your pants. This is how you can tell your rotors have warped and in what location.
- Is it dangerous to drive with warped rotors?
As previously mentioned it is the responsibility of the rotors as part of the disc brakes that allows your truck or car to stop once it is in motion. “Why does my truck shake when I brake?” This will not be the only question you will be asking the mechanic if you insist on driving with warped rotors.
If the rotors are warped, your vehicle may also not be able to stop at the right time in an emergency situation. This can be very dangerous if you need your brakes to work to avoid a vehicular accident, a pedestrian, or another driving situation that calls for it.
So as soon as you start to realize the brakes are not working properly, and check for warped rotors. If you insist on driving with warped rotors then here are some things you have to know.
- Rotors and other components of your brake system like calipers, pads have to be inspected because they do wear down over time, and you have to do this on a regular basis.
- Again, a warped rotor is equal to decreased stopping time. The surface may be smooth but the vehicle will still take longer to come to a stop and if the warped rotor is located on the drive axle then the stopping time will be more noticeable.
- A warped rotor causes the brake pads to wiggle back and forth, and that causes the brake fluid to foam up so the braking system will not be able to get the proper amount of hydraulic pressure causing your brake to temporarily fail. If that happens you may hit vehicles around you.
- Noises like thumping or a pitched hum, when you hit the brake is another sign of warped rotors. This noise may come from contacting the brake pads unevenly.
Knowing all these, you must know already that driving with warped rotors will potentially result in a brake system failure. So the short answer to the question is yes, it is dangerous to drive with warped rotors.
Why Does My Truck Shake When I Brake…To sum it up…
If you had to ask, “Why does my truck shake when I brake?” Then it’s time to take action and have it investigated and fixed. A shaking brake pedal will affect your vehicle’s braking performance, and when you are talking about braking issues it is something that can greatly compromise vehicle safety. So you should be cautious and address the issue Immediately. Braking issues makes handling your vehicle more difficult posing a danger to yourself or others if it worsens.